They must now go by their own soundings, and this would be especially dangerous in the close neighborhood of half-submerged mountains, whose buttresses and foothills might rise suddenly out of the depths with slopes so steep that the lead would afford no certain guidance. It was first necessary to learn if possible the actual height of the water, and whether it was still subsiding. It was partly for this purpose that they had passed over Egypt instead of keeping directly on toward the coast of lower Palestine. But now Cosmo abandoned his purpose of taking his measurement by the aid of Mount Sinai or some of its neighboring peaks, on account of the dangerous character of that rugged region. If they had been furnished with deep-sea sounding apparatus they might have made a direct measurement of the depth in Egypt, but that was one of the few things which Cosmo Versál had overlooked in furnishing the Ark, and such an operation could not be undertaken. He discovered that there was a mountain north of the Gulf of Akaba having an elevation of 3,450 feet, and since this was 220 feet higher than Monte Lauro, in Sicily, on which the Ark had grounded, he counted on it as a gage which would serve his purpose. So they passed almost directly over Suez, and about 120 miles farther east they found the mountain they sought, rising to the west of the Wadi el Arabia, a continuation of the depression at whose deepest point lay the famous "Dead Sea," so often spoken of in the books of former times. Here Cosmo was able to make a very accurate estimate from the height of the peak above the water, and he was gratified to find that the recession had not continued. The level of the water appeared to be exactly the same as when they made their unfortunate excursion in the direction of smoking Etna. "It's all right," he said to Captain Arms. "We can get over into the Syrian desert without much danger, although we must go slowly and carefully until we are well past these ranges that come down from the direction of the Dead Sea. After that I do not see that there is anything in our way until we reach the ancient plains of Babylon." King Richard, who was full of the history of the Crusades, as well as of Bible narratives, wished to have the Ark turn northward, so that they might sail over Jerusalem, and up the Valley of the Jordan within sight of Mount Hermon and the Lebanon range. Cosmo had had enough of that kind of adventure, while Captain Arms declared that he would resign on the spot if there was to be any more "fool navigating on mountain tops." But there were many persons in the Ark who would have been very glad if King Richard's suggestion had been carried out.